簇状分布的刚性双层植被明渠紊流特性分析

Analysis of turbulent characteristics of open chanel flow with patchy distributed double-layer rigid vegetation

采用RNG k-ε紊流模型,对簇状分布的刚性双层植被明渠水流进行了模拟和分析;根据时间及空间的双平均方法对植被明渠水流的流速及紊动参数进行了统计。结果表明:簇状分布的植被明渠水流可以分为植物区、间隙区及主流区,不同区域时均流速的大小和分布各异;双层植被明渠水流中,时均流速垂线分布在近床面、低植物顶部附近及高植物顶部附近均出现拐点,脉动强度和紊动能的最大值出现在高植物顶部附近。

The RNG k-εturbulence model was used to simulate and analyze the open channel flow with patchy distributed double-layer rigid vegetation.The flow velocity and turbulence parameters of the open channel flow with vegetation were statistically analyzed based on the double-average method of time and space.The results show that the open channel flow with patchy distributed vegetation can be divided into vegetation zone,gap zone,and mainstream zone,and the magnitude and distribution of time-averaged flow velocity vary in different zones.In the open channel flow with double-layer vegetation,the vertical distribution of time-averaged flow velocity exhibits inflection points near the bed surface,near the top of the low plants,and near the top of the high plants,and the maximum values of fluctuation intensity and turbulence kinetic energy occur near the top of the high plants.